Re: F4i Front Fork Vibration Problem
First obvious thing to check is the tire for wear and proper air pressure. I've noticed a worn front tire causes some bad steering, turning, and braking issues...also can cause vibration.
It shouldn't be fork shims, i wouldn't think... i mean, what can change inside of a fork.. everything inside a fork is preset and stays in place. The only copper washers i know of on forks is for the the dampening rod bolt..where it bolts through to the fork leg to keep oil from leaking out. This copper washer is located where the wheel axle slides through the fork. Were your forks leaking any oil at the bottom of either fork leg? Being low on fork oil will cause problems.
As mentioned above steering head bearings being worn or lose can cause vibration and some weird feelings in the front end.
wheel bearings, again like stated, can cause vibration and wobble feeling in the front end. Makes the front end feel weird in corners and unstable.
That can be checked by lifting the bike up onto a front fork stand, unbolt the calipers and hang them out of the way. Place on hand on the front of the wheel, the other on the back and rock the wheel slightly to feel for any loose play.